Diop provoked outrage among the Atletico players by dancing in front of the disconsolate travelling fans at the final whistle.

However, the Senegalese said he was just responding to monkey chants aimed towards him as he took a corner deep into stoppage time.

"I went to take a corner and some of the Atletico fans began to make monkey chants. To play it down, I started to dance, but I didn't insult anyone.

"I don't have anything against the Atletico fans because it was only a section that shouted. It is a lack of respect that happens in all stadiums. I don't know if you can call it racist, but the monkey chanting has to stop."

It is the second time in a week that Spanish football has been rocked by a racist incident after Barcelona defender Dani Alves took a bite out of a banana thrown at him in his side's win over Villarreal last weekend.

The culprit at El Madrigal was subsequently arrested and handed a lifetime ban from the stadium by Villarreal.

Alves' action also provoked an international anti-racism campaign across social media with star players of different nationalities and races including Neymar, Sergio Aguero and Luis Suarez lending their support to the "we are all monkeys" campaign.

"Spanish football must face up to the fact that they have a serious racist problem. They can't continue to bury their heads in the sand," tweeted former England international Gary Lineker who once played for Barcelona.